U0501 code meaning
Invalid Data Received From Door Control Module B
What U0501 means
Many cars give each door its own electronics: a door unit receives commands over CAN and drives window lift, lock and mirror, as a Yazaki patent describes with a LIN sub-bus inside the door. Module A has its invalid-data code in U049A; U0501 is the same check for the second door unit. The body controller or another listener gets B's frames, for instance lock status, window position or switch inputs, but finds them implausible, out of sequence or with a bad checksum. Which door B serves is not standardised, and no carmaker documents U0501 publicly. GM's Saab 9-5 list, for one, has no partner entry U0200 for it. Silence from B gives U0200. The driver may notice one door that no longer locks centrally or whose window switch is ignored.
U0501 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0501
- One door not following central locking
- Window, mirror or door-ajar display of that door erratic
Common causes of U0501
- PossibleWater ingress into the door module through a failed door membrane
- PossibleBroken wires in the harness grommet between body and door
- PossibleDoor module not programmed or configured after replacement
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Door control module b
What each part of U0501 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 01 | The exact fault in that area. |
What to do next
- Note U0501 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U0501
What does U0501 mean?
U0501 means "Invalid Data Received From Door Control Module B". Many cars give each door its own electronics: a door unit receives commands over CAN and drives window lift, lock and mirror, as a Yazaki patent describes with a LIN sub-bus inside the door. It is a generic code, so it means the same on every make.
Is it safe to drive with U0501?
U0501 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0501 fail an emissions test?
U0501 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U0501 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U0501 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.